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Biomedical subjects

C Kennedy

Publications and source records attributed to C Kennedy.

At least 19 recordsLinked to original sources

Respiratory system of Gluconacetobacter diazotrophicus PAL5. Evidence for a cyanide-sensitive cytochrome bb and cyanide-resistant cytochrome ba quinol oxidases.

In highly aerobic environments, Gluconacetobacter diazotrophicus uses a respiratory protection mechanism to preserve nitrogenase activity from deleterious oxygen. Here, the respiratory system was examined in order to ascertain the nature of the respiratory components, mainly of the cyanide sensitive and resistant pathways. The membranes of G. diazotrophicus contain Q(10), Q(9) and PQQ in a 13:1:6.6 molar ratios. UV(360 nm) photoinactivation indicated that ubiquinone is the electron acceptor for the dehydrogenases of the outer and inner faces of the membrane. Strong inhibition by rotenone and capsaicin and resistance to flavone indicated that NADH-quinone oxidoreductase is a NDH-1 type enzyme. KCN-titration revealed the presence of at least two terminal oxidases that were highly sensitive and resistant to the inhibitor. Tetrachorohydroquinol was preferentially oxidized by the KCN-sensitive oxidase. Neither the quinoprotein alcohol dehydrogenase nor its associated cytochromes c were instrumental components of the cyanide resistant pathway. CO-difference spectrum and photodissociation of heme-CO compounds suggested the presence of cytochromes b-CO and a(1)-CO adducts. Air-oxidation of cytochrome b (432 nm) was arrested by concentrations of KCN lower than 25 microM while cytochrome a(1) (442 nm) was not affected. A KCN-sensitive (I(50)=5 microM) cytochrome bb and a KCN-resistant (I(50)=450 microM) cytochrome ba quinol oxidases were separated by ion exchange chromatography.

Bacterial Proteins↗

Atypical cutaneous leishmaniasis in two patients receiving low-dose methotrexate.

Cutaneous leishmaniasis is a protozoan disease that has high morbidity. There have been increasing reports of leishmaniasis in patients with an underlying immunosuppressed state. We present two cases of cutaneous leishmaniasis caused by Old World species in patients on methotrexate therapy. We postulate that the T-cell-mediated response to leishmaniasis infection could be modulated by methotrexate and may render an immunosuppressed individual more susceptible to developing clinical disease.

Adult↗

Spontaneous coeliac artery dissection.

A patient with spontaneous coeliac artery dissection that presented as upper abdominal pain is reported. This was diagnosed on contrast-enhanced multislice helical CT. The patient was treated conservatively and follow-up CT showed mild aneurysmal change of the splenic artery and a small splenic infarct. Isolated dissection of the visceral arteries (and, in particular, the coeliac artery) is extremely rare. With such limited evidence, decisions over best management are difficult, but depend on initial severity and progression at follow up.

Aortic Dissection↗

Comparison of concentrations of Rhodococcus equi and virulent R. equi in air of stables and paddocks on horse breeding farms in a temperate climate.

REASONS FOR PERFORMING STUDY: Rhodococcoccus equi is a significant cause of bronchopneumonia in foals worldwide. Infection of the lungs is believed to result from inhalation of virulent R. equi in dust from contaminated environments. A measure of infectious risk in an environment is the level of airborne contamination. OBJECTIVES: To assess and compare the level of airborne virulent R. equi in paddocks and stables. METHODS: Air samples were collected sequentially over the 2003 foaling season from the paddocks and stables on 3 Irish horse breeding farms affected by R. equi pneumonia. Colony blotting and DNA hybridisation techniques allowed quantitation of virulent R. equi. RESULTS: The odds of detecting airborne virulent R. equi in stables were 173 times greater than in paddocks. The median airborne concentration of virulent R. equi was significantly higher (P < 0.001) in stables than in paddocks on all farms. These observations suggested that stables were high-risk areas for infection. CONCLUSIONS AND POTENTIAL RELEVANCE: Our results indicate that contaminated stables are a significant risk factor in the epidemiology of R. equi pneumonia on horse-breeding farms in a temperate climate, such as in Ireland. Management strategies that improve the air hygiene of stables, through better ventilation, use of less fragile bedding material and the use of fogging agents to reduce the airborne concentration of virulent R. equi, may reduce the incidence and severity of R. equi pneumonia on farms.

Actinomycetales Infections↗

Cultural variations in children's coping behaviour, TV viewing time, and family functioning.

AIM: To examine children's coping behaviour, TV viewing hours and family functioning in four ethnic groups and factors related to children's coping behaviour. METHODS: This study was part of two larger research projects investigating children's health behaviours in the United States and Taiwan. Fifty-six White American children of European ancestry, 66 Mexican American children, 68 Chinese American children and 95 native Taiwanese children were included in the analysis. Standardized instruments were used to measure coping strategies, children's TV viewing hours and family functioning. RESULTS: There were significant differences in the types of stressor that children of different ethnicity reported. Similarities and differences were found in the four ethnic groups regarding the top five most frequently used and most effective coping strategies. Multiple regressions identified two variables that contributed significantly to the variance in the frequency of children's coping strategies--ethnicity and poorer behaviour control in the family. Ethnicity was the only variable found to contribute to the variance in coping effectiveness. Significant differences were found in the number of hours children spent watching TV. CONCLUSIONS: Findings suggest that children of different ethnicity utilized different types of coping strategies and ethnicity is one of the important factors related to children's coping behaviour. These findings provide evidence for nurses to assess children's coping behaviour and TV viewing and provide children with healthier alternatives.

Adaptation, Psychological↗

Evaluating clinical signs in trabeculectomized eyes.

AIM: To evaluate interobserver agreement for clinical signs in trabeculectomized eyes when examined face-to-face with slit-lamp biomicroscopy (SL) or by remote examination using telemedicine (real-time remote video imaging; TM). METHOD: A system for examining trabeculectomized eyes was devised and validated. A prospective randomized interobserver agreement study was then undertaken to compare standard SL biomicroscopy and TM. Remote examination was performed using a 384 kbps Sony 5100 videoconferencing system. Three ophthalmologists each examined 40 eyes of 40 patients, who had previously undergone trabeculectomy. In rotation, two examiners used SL biomicroscopy. The third examined the eye remotely by TM. Analysis was performed to determine the variability in clinical signs and the presence or absence of systematic bias between ophthalmologists and examination methods. RESULTS: High levels of agreement were observed for paired examinations by SL biomicroscopy (SL/SL) for bleb vascularity (score range 0-10) with no systematic bias. Paired examination by SL and TM (SL/TM) also showed good levels of agreement for bleb vascularity, although the spread of disagreement was wider (95% limits of agreement 2.57 vs 2.98 (P=0.054)). For anterior chamber depth, observers agreed within +/- 10% of anterior chamber depth for 68% of eyes (SL/SL) and 51% of eyes (SL/TM) (P=0.68). Agreement was 'good' for wall thickness (kappa=0.63 +/- 0.08), bleb height (kappa=0.67 +/- 0.1), and the existence of bleb leak (kappa=0.63 +/- 0.19), but poor for bleb morphology (kappa=0.26 +/- 0.12). For the SL/TM comparison, agreement was fair for wall thickness (kappa=0.39 +/- 0.13), poor for bleb height (kappa=0.17 +/- 0.12), good for bleb leak (kappa=0.56 +/- 0.19), and fair for bleb morphology (kappa=0.31 +/- 0.12). Microcysts were not reliably detected using either technique. CONCLUSION: SL biomicroscopy and TM telemedicine examination may permit reliable clinical assessment of trabeculectomized eyes. However, remote examination with TM is more limited with respect to assessing bleb height and bleb wall thickness. The assessment of bleb morphology and microcysts was unreliable with both instruments. We propose that TM examination of trabeculectomized eyes appears safe and appropriate in situations where face-to-face examination by an ophthalmologist is not practical.

Anterior Chamber↗

The cost-effectiveness of technology transfer using telemedicine.

The high burden of disease in developing countries often makes it difficult for health systems in these countries to attain the same level of specialist skills as industrialized countries. Technology transfer is one way to improve specialist skills whilst at the same time reducing the burden of disease. This paper describes the use of teleophthalmology, a form of telemedicine, as a mode of technology transfer between the United Kingdom and South Africa. As the burden of eye disease in South Africa is high, the country cannot afford the level of ophthalmic specialization achieved in the UK. The paper estimates the cost-effectiveness of the technology transfer project in terms of a cost per Disability Adjusted Life Year (DALY) averted. We found the technology transfer project to be cost-effective in reducing the burden of eye disease, and that practitioners in South Africa also learned novel procedures that could help future patients and improve cost-effectiveness. Technology transfer using telemedicine is a cost-effective method that richer countries can employ to aid capacity building in the health care systems of poorer countries.

Cost of Illness↗

A case of monocytic leukaemia cutis in a patient with myelodysplastic syndrome transforming to acute myeloid leukaemia.

A 49-year-old woman presented with a 1-year-history of a widespread eruption which proved to be due to leukaemia cutis. Subsequently, she developed pancytopaenia and a bone marrow biopsy revealed refractory anaemia with excess blasts in transformation (RAEB-T) with a high monoblastic component. This transformed into acute myeloid leukaemia. Leukaemia cutis in this context is well described but in this patient it became manifest 1 year prior to referral to the dermatologist. When occurring with a myelodysplastic syndrome, leukaemia cutis often heralds malignant transformation to acute myeloid leukaemia. Prompt diagnosis in this situation may identify a group of high-risk patients with myelodysplastic syndrome for whom chemotherapy and allogenic bone marrow transplantation, rather than the more conventional approach of supportive treatment, could be a more appropriate management strategy.

Anemia, Refractory, with Excess of Blasts↗

Identification of new HLA-C alleles by polymerase chain reaction-sequence specific oligonucleotide typing: Cw*0314 and Cw*1511*.

In this article, we report two new human leukocyte antigen-C (HLA-C) alleles, HLA-Cw*0314 and Cw*1511, which were identified during routine tissue typing of donors for the Australian Bone Marrow Donor Registry and Australian Cord Blood Bank. HLA-Cw*0314 shows six codon changes in exon 3 compared to Cw*030401 and shares some sequence homology with Cw*07 alleles. Cw*1511 has two nucleotide changes compared with Cw*150201 in exon 2, both resulting in amino acid changes in the protein sequence.

Alleles↗

Behavioural, emotional and family functioning of hospitalized children in China and Hong Kong.

PURPOSE: This study examined behavioural and emotional problems, social competence and family functioning of hospitalized Chinese children in Hong Kong and the Chinese Mainland. METHOD: A sample of 210 hospitalized children (ages 2-11 years) and their families participated in the study. The families were from a cross-section of geographical areas in Hong Kong (two hospitals) and the Chinese Mainland (five hospitals). Parents completed an age-appropriate Chinese version of the Child Behaviour Checklist and the Family Assessment Device. Multiple regression models were used to examine predictors of children's behaviour problems. RESULTS: Behavioural patterns appeared to be specific to the developmental stage. Children had greater problems when their families demonstrated poorer affective involvement. Hospitalized children on the Chinese Mainland experienced more internalizing and externalizing behaviour problems than those in Hong Kong. Sick children, according to their parents, however, demonstrate some resiliency based on social and academic competency factors. CONCLUSIONS: Hospitalized Chinese children manifest behavioural, emotional and family problems that vary by region, the child's development and gender. Problems predominantly of an internalizing nature characterized this group. The findings support the need for culturally appropriate behavioural assessments and interventions with hospitalized children.

Adult↗

Universal neonatal hearing screening moving from evidence to practice.

Recent technological advances have made feasible universal newborn hearing screening and therefore early detection of permanent childhood hearing impairment. Over the past three years, new information has been published on whether early intervention is beneficial, the possibility of harm arising from newborn screening, and its cost. Dramatic progress has been made in the large scale implementation of universal screening in many parts of the western world.

Health Policy↗

Crossing the pain barrier: P2 receptors as targets for novel analgesics.

In 1995 the P2X3 receptor was found to be expressed at high levels in nociceptive sensory neurones, consistent with earlier reports that ATP induced pain in humans and animals. At first it was thought that ATP was most likely to play a role in acute pain, following its release from damaged or stressed cells and since then a wide variety of experimental techniques and approaches have been used to study this possibility. Whilst it is clear that exogenous and endogenous ATP can indeed acutely stimulate sensory neurones, more recent reports using gene knockout and antisense oligonucleotide technologies, and a novel, selective P2X3 antagonist, A-317491, all indicate that ATP and P2X3 receptors are more likely to be involved in chronic pain conditions, particularly chronic inflammatory and neuropathic pain. These reports indicate that P2X3 receptors on sensory nerves may be tonically activated by ATP released from nearby damaged or stressed cells, or perhaps from the sensory nerves themselves. This signal, when transmitted to the CNS, will be perceived consciously as chronic pain. In addition, it is now clear that several subtypes of P2Y receptor are also expressed in sensory neurones. Although their distribution and functions have not been as widely studied as P2X receptors, the effects that they mediate indicate that they might also be considered as therapeutic targets in the treatment of pain. Although our ability to treat persistent painful conditions, such as chronic inflammatory and neuropathic pain, has improved in recent years, these conditions are often resistant to currently available therapies, such as opioids or non-steroidal anti-inflammatory drugs. This reflects a limited understanding of the underlying pathophysiology. It is now clear that the development and maintenance of chronic pain are mediated by multiple factors, but many of these factors, and the receptors and mechanisms through which they act, remain to be identified. Chronic pain is debilitating and can greatly decrease quality of life, not just due to the pain per se, but also because of the depression that can often ensue. Thus a greater understanding of the mechanisms that underlie chronic pain will help identify new targets for novel analgesics, which will be of great therapeutic benefit to many people.

Adenosine Triphosphate↗

Provision of hepatitis B vaccination for primary care dental staff in Scotland.

OBJECTIVES: All dental surgeons should be protected from hepatitis B virus (HBV) infection by immunisation, ideally administered and monitored via occupational health services (OHS). This study examined relevant OHS systems in place for dental primary care healthcare workers (DHCW) across all Health Board Areas (HBAs) in Scotland. It also explored the DHCWs' knowledge of, and access to, these systems in three HBAs. METHODS: Data from senior staff in all Scottish Health Boards and Primary Care Trusts were collected by self-completing questionnaires. Information from DHCWs was collected via telephone interviews with General Dental Practitioners (GDPs) and Community Dental Officers (CDOs) in each of Ayrshire and Arran, Highland and Lothian Health Boards. RESULTS: Thirteen of the 15 HBAs had robust HBV vaccination and monitoring systems. However, only 7/15 (47%) of these covered all DHCWs. Seven HBAs provided vaccination and monitoring for CDOs only, leaving GDPs to undertake these responsibilities for themselves. Of the 105 DHCWs approached, 82 gave an interview. These interviews highlighted major differences between HBAs in relation to access of DHCWs to OHS and indicated that CDOs had greater access than GDPs to OHS. Overall, 31% of DHCWs were not satisfied with the OHS available. CONCLUSION: In order to safeguard both staff and patients, significant further work is required to ensure that all DHCWs have access to appropriate OHS support for provision and monitoring of immunisation procedures and related functions such as management of sharps injuries.

Chi-Square Distribution↗